New homemade hollowing rig

[Rob Miller]

Well, I built myself a home-made hollowing rig. Tried it out today and it seems to work pretty well. I'm using a round carbide cutter. A question for you -- do those of you who use such a rig prefer to use the blade on the horizontal plane or at an angle, say 30-45 degrees? Justify your choice. ;-)

[Grant Wilkinson]

I have a store-bought rig that uses an 8mm round cutter. It's a dished cutter, not a flat top one, so my experience may differ from yours. I tilt the cutter to about 30 degrees. I don't measure the angle, but it's more vertical than 45 for sure. I justify my choice :-) by the cut that I get. The more horizontal I turn the cutter, the more grabby it gets. It takes off more wood, for sure, but it's tough to control inside the hollow form and the surface is not as clean.

[Thom Sturgill]

Without pictures I'm not sure whether you are talking about just a hollowing bar or a captured/articulated system. I have a small cutter I use on my controlled systems that I bought from Lyle Jameison. It is on an angle for a shear cut and works fairly well. I put a carbide tip on a small hand held goose-neck hollower (from Sorby) - it sits flat and tends to be grabby. I prefer the HHS bits in my Ellsworth and Jordon bars better as I find the carbide cutters to be a bit too aggressive.

[John Keeton]

Just know that with any cutter on an angle - round or HSS bar stock, will catch quickly if introduced to the wood on the back side of the angle. In other words, inside a form DO NOT permit the angled cutter to touch what would be the bottom of the form if you have it set to hollow the top/shoulder portion. At that point, the cutter is in a positive rake position and the results will not be pleasant!

[Eric Gourieux]

Just know that with any cutter on an angle - round or HSS bar stock, will catch quickly if introduced to the wood on the back side of the angle. In other words, inside a form DO NOT permit the angled cutter to touch what would be the bottom of the form if you have it set to hollow the top/shoulder portion. At that point, the cutter is in a positive rake position and the results will not be pleasant!


How did you know that, John? :D

Rob, until you learn the particular cutting characteristics of a cutter, it's always best to start with the cutter at an angle. If you don't get the cut that you want, you can always adjust the angle.

[John Keeton]

How did you know that, John? :DLet's just say it was a moment of enlightenment!! A very quick moment!!;)